They warn of the risks of not cleaning the bottles properly

The professor of the Master of Sustainability and ESG Management at the European University, Miguel Aguado, has warned that poor hygiene of the reusable bottlesespecially in rubber gaskets and lid spouts, can cause gastrointestinal problems.

Components like Rubber gaskets, retractable spouts or internal straws can become sources of mold and bacteria accumulation if not cleaned properly. “The most critical part is not usually the body of the bottle, which is easy to clean, but precisely the lid and its mechanisms,” said Aguado.

The expert has stressed that these nooks, designed to guarantee watertightness or facilitate consumption, create an ideal environment for the proliferation of microorganisms. “When there is moisture and organic matter, microorganisms find a comfortable place to settle”he added.

Although for a healthy person the risk of consuming water from a bottle with these biofilms is usually low, it is not harmless, warns Aguado. The presence of mold or bacteria can cause mild gastrointestinal discomfort, irritation or opportunistic infections. “The risk may be higher in young children, older people, or people with a weakened immune system.which are more sensitive to microbial exposure,” emphasizes the expert, who added that a persistent odor, even after washing, is a clear warning sign.

To ensure proper hygiene, Aguado explains that it is not enough to rinse the bottle: “Correct protocol includes a daily cleaning with hot water and soap, disassembling all the parts of the lid whenever possible.” Thus, it indicates that it is essential to use a small brush to access the internal mechanisms and, above all, let all the components dry completely separately before reassembling the bottle.

For the expert, The simplest designs are the safest from a hygiene point of view. “A simple screw cap is the easiest to clean,” he adds, however, sports caps, internal straws and retractable nozzles, common in children’s bottles, “are usually accompanied by greater complexity when cleaning.”

Prevention is, therefore, the key to responsible use. Aguado insists on the importance of periodically check the cover and replace it if there are signs of deterioration such as persistent mold stains, deformations in the joints or a malfunction of the mechanism. “Recognizing when it is time to change a part is part of responsible and healthy use,” he concludes.